美国麻省理工学院Sallie W. Chisholm等研究人员合作揭示海洋生态系统中新的整合元件和基因组的可塑性。相关论文于2023年1月5日发表于国际学术期刊《细胞》。

Title: Novel integrative elements and genomic plasticity in ocean ecosystems

Author: Thomas Hackl, Raphal Laurenceau, Markus J. Ankenbrand, Christina Bliem, Zev Cariani, Elaina Thomas, Keven D. Dooley, Aldo A. Arellano, Shane L. Hogle, Paul Berube, Gabriel E. Leventhal, Elaine Luo, John M. Eppley, Ahmed A. Zayed, John Beaulaurier, Ramunas Stepanauskas, Matthew B. Sullivan, Edward F. DeLong, Steven J. Biller, Sallie W. Chisholm

Issue&Volume: 2023/01/05

Abstract: Horizontal gene transfer accelerates microbial evolution. The marine picocyanobacterium Prochlorococcus exhibits high genomic plasticity, yet the underlying mechanisms are elusive. Here, we report a novel family of DNA transposons—“tycheposons”—some of which are viral satellites while others carry cargo, such as nutrient-acquisition genes, which shape the genetic variability in this globally abundant genus. Tycheposons share distinctive mobile-lifecycle-linked hallmark genes, including a deep-branching site-specific tyrosine recombinase. Their excision and integration at tRNA genes appear to drive the remodeling of genomic islands—key reservoirs for flexible genes in bacteria. In a selection experiment, tycheposons harboring a nitrate assimilation cassette were dynamically gained and lost, thereby promoting chromosomal rearrangements and host adaptation. Vesicles and phage particles harvested from seawater are enriched in tycheposons, providing a means for their dispersal in the wild. Similar elements are found in microbes co-occurring with Prochlorococcus, suggesting a common mechanism for microbial diversification in the vast oligotrophic oceans.

DOI: 10.1016/j.cell.2022.12.006

Source: https://www.cell.com/cell/fulltext/S0092-8674(22)01519-7